How bad is the original that you need to replace it? The only supplier that showed the 671-186X was Dew Associates, and sadly it is "OUT OF STOCK". All the other suppliers I have bookmarked, only list the 1947 style in stock. There is an alternative, if the original isn't badly damaged. You can try to use Card Stock, like poster board, and make one, by tracing the outline of the original. Then use an Xacto knife to cut the slits, and use small drill bit to make the screw holes. I have done it once, on the 1947 version, just to get the loco back together, and it worked for me. It is a thought that you may want to try.